SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ca3cea1659043afd3d9cfac918f31f9513521e2575ded52e97a4a0b0d4c79e03' 
  AND token = 'ETlnfANd9cBPprAj5nncZScz4i0RhsICScE3Dw7eh4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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