SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e0aa91f36f6e6dc95aa3a0b498194a8d22535b86405aa545f94585705232baec' 
  AND token = 'pbc9znjrxCSR3dAm3/aPNspltL+yeyqWL3jzH4hlIlw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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