SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7b00fd449bc0c452ffcf33adb3766051cb93373666276cc51eec43994ccf5224' 
  AND token = 'nlI1nbKN1npgQIkB8l2pywV8W77wnEu7P87wT3idDu4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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