SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc0f663b234b2228417df67d19f4450a055fb7d599fd5e5b59233e14ee537266' 
  AND token = 'Ik5L4Y9XGUYzmexFweHf03zfK13/BkSPvnTT+GBSoqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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