SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '83ffe7dc17668cd084b3f6c0428b60370d4fda72805f04aa3ada684535c74a6b' 
  AND token = 'CoRv/XDHJQw/+xGyIejeVnKbkWRT5+w6KfAWjE7lHmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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