SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cea50d72e2df8870c97ca75a8f16e5a2cd6361125a37c62b3749e11ead2f3596' 
  AND token = '0yUCrVjcxqtdBUR8DuuH3ADfeOWeTdsSQCNUDJXIdRA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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