SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6225c102e02ac89777249751dcf466419918be252eca836ab5d9f0e12ef139c6' 
  AND token = 'g4NSqu5feNFpITFD5TyRbj5aDrKocV35OHJ167EakiA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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