SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b03e425746217bdc9c9e8bc2d0f2fda8c299765697b22a1f60241182f22db9e1' 
  AND token = '1Hxp6+g1WCZjJ0UGJHU4pw7kjEEQ8J5gbExREGi3kWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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