SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b16e562fda8e2bcaccd5a922ca24ead936ad4749f1c0ec1d0758f17713196e73' 
  AND token = 'aI1vsIxsx3wDg0EMVaqAw9h5DwfCNUawNjRe/0yRN7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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