SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0c2dd3d3e391c586962b8c48f8491c8fe8fb958da0dd997efe27811c12bd1b4' 
  AND token = '6ojNZg+jAVm4K21LWTHaKpVv6evgvzKQqcw8itlERco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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