SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c66aadf371569db501741c3971004af959dbb122f858bffb8efcce34ce0058b0' 
  AND token = '2UFJdpozfqfJeWTpmfmrA+8zcZAw5yhUmrIuNR12eEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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