SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7c98b83dfc0a0307b807f4168552fac34c36ecb64a5a97d9dd306d2fc9bf92c' 
  AND token = 'lJY9c6OqV7aSaNhx4rRK6t9/zBklI3BKJLmN+NWUBCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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