SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '12ec70ac14672780d35d8e14411f97a630239f1b7e57789cf172c7bf841cf2c4' 
  AND token = 'id7jeoYCS5ZzKsduPuFDVsDldF+Glc9stQG1xyUEs0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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