SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bc753b0c21d5dbb8bf29423a1ef381e63385f98ed750937e203206b0562a23b' 
  AND token = 'y8btoHTgTl+cXkJYdc0KI4TqBqXJgBzZOeBsMUUV3JE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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