SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88901c0b3149a3f68693b1a7af4327191fd12de6ef3a6465f31880915a315db1' 
  AND token = 'aadnE40hLnLlGG1UYbpfJrYfonuxGhpdBtWjQVofA3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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