SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c52bcdc6600b5764ffe48a1c0922c431a631ab320d0d31abdcac67b8773d34c2' 
  AND token = 'rNN4v6FwmuU4/Z/kRDSuGMA0WQWlMP4k2pcjA1pOGOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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