SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '612988960811ede5275da10facfa850d9262026acc6bbd4d852402d636f1f57c' 
  AND token = 'WoMMJnhThjCJ2zOjpA3T3ONODJ/dumHsAsW439H6W3s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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