SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd46688de9673736a99b27d701d3805c23d4078d82db297779effa3cd7dfebdfd' 
  AND token = 'cqiPQ8ViegR5yOnQAJv0nDlb5GzME/KZjEDFTFCXBHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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