SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '242fe6f577a9fa382150d732bbdada8f4fd1d614655ed9f96ca310d69467c8b7' 
  AND token = 'mb45VpGlC2b2Yri834W/+TS+cCviOC7FMTMyxGUOQcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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