SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '293d1aca2c92f05035a4aa08ae63fd20a7290e9d73ad36decfdaff0fac477e06' 
  AND token = 'IA/kKsqI4G6JLBdeoj7eKUEXvBYWF8qgJjZty8w9Czc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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