SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c081a1661226878031cb92675c4f85c59b0740bf94dd105b77f0c98bd95cced7' 
  AND token = '+Nw8ABKjvPjTsF5O4+R+ZXCZ5ZNcZRmN1L7sOpBTrgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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