SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2952c43daf2f9676248f9ec8849a7a1b8c09b382e87569adbfc13842f17991cd' 
  AND token = '7NcB8gflefodw/flQcAA+CRmcuCpcRTq44jmBLkTjek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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