SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a996057b66aa548b99f4dbeed9a8e4c9988d2c0922683d604bcd90d60a285afd' 
  AND token = 'Erb/MfdC2Ax74G/fFaDLd9V96BLeq0Q1Du2HCt9o9hc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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