SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35012445a7cd48c889ead9203c900e2cef53c5df738034d1605c54e45e6cf00a' 
  AND token = 'BPrPjXP5Vz/DtzPzbLlhUPqCHqogP+H5TN+YzgOwIwU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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