SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7ecdcb648538612ef2a0ca1df798b7d98fa5c5c014bab47c2adb1cadb326b5fb' 
  AND token = '5Dl9GVwTpvhDl8Q1M/seP1o47+/s2us8K9+6YCx3Igs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}