SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7deb03e8a48393b0879ca54f6d29354c9047f6ff0fa768af23e96c6923786e14' 
  AND token = 'Td72Gi+1gXvuWhz4/pwMEGUQ/EAXpQzCxQMLbpPbUv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

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