SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d41a8cbb2a9d010156a1f6e2a6f2304f56b8c1986af5beed18a2d8cecaa911d' 
  AND token = 'AgvPsz0hk+G1W9MpJrb9eZSghxkwDGeHu9fVG13hYKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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