SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dcab56279a785fb07c6cf998fd250b6bce3c72f560a508633f850278def1dc06' 
  AND token = '9LOOXzBJBMexnEk+MZqw2egGysyRgiWy2FYmu4/cNdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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