SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '586d66410b249c70e9431b63bd246ebe8697632c940badd6e69da14124dcb961' 
  AND token = 'b1l1VigEEa/xGDk+iVG/+yMa6FH1elKQAxCvU8RSrX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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