SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b8f416de2fa0b14a5dd85a6152bdee2d11a0d336feb77a63cf9ee50096cb0762' 
  AND token = 'wh+2qbG80KjyzHV+fmMYBRXW8JrkbAjQKdpMvbAtOO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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