SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e0b26a63cd8ccf42a21bc1bab4b7e3af70b761d51e9964548f9f768cbeb72a3' 
  AND token = 'Xq6YGgksoMvi0/xtayzLRRHmNGP3OGwOiD3JZ2WQMn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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