SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb489952c6abe18d1f70993993fbb70ab1cc77140905b89c314c933f7c4570eb' 
  AND token = 'qy49uPgFivtA47IOxVSRmwAXgEeE2pfMqYQJPpJeprc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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