SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4ef4031746d3b463e15dd1986fe3c186f64f32eae1c8d006b2f2ef8f92d6c54' 
  AND token = 'Ly4163RMZ9j/likuqfNajAIF4BQ7/3olFEFgncNkfOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}