SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f232f6d68b80b85d53937ccc56bf32ad432fa6d812bbabe933cdd2634e751ef3' 
  AND token = 'ldmds7pP3+Z/KCHSymVP5MGDuGY5pIyUHEe+5EbH7tk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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