SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c00fcf4751b70b8a79175cd2b294b96724f8c472e3485b49afa9917efda32cb1' 
  AND token = '3GBcWcCTluwV0hF2PjOC+TZQd8B+/ykY2bW88qNWSzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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