SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7c8f92c5c00d50b45fa46bf3bd48701c87ee9084a34442b698186c28ee119c5' 
  AND token = 'twhDxW9/X3nGZxs66DepYAFsP0fpbuff9KxCZeGTBoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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