SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53a44880f667f252f754f9674c52d9d25683c367cdf6929daf7fa4ce450d3811' 
  AND token = 'uB4jovsqFn9rKREEi9mqpmJXh7gb7vRi+pBkz0zy4as=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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