SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abe1830bc1c1f2623a2499f3938487daabff1bfb382ac29110607dea06445891' 
  AND token = 'PmJPwaYZup2pj0gi/u8rJnqxck8rnLzz597K6n/IvKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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