SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4493739bac79918c45f5a0ef40cc4ae22164c1a20610949e905f700633f62553' 
  AND token = 'G2fZvNkARK+qzIyv1hFhU4ynYMtfdZKI0HQAAbxvquU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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