SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10da44a652f0b9d33c8329b35da1ef139bba2f401685e1be6e6528bb9ab964e4' 
  AND token = 'FyTEX1WELBOUM42kfWYNiytWCxSbMs8HeyBuFpDXRnM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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