SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8524d94c7561768c87534ba1832c180dfcc07855651310b29d5bdd02beffe8a2' 
  AND token = 'QxIbVkBZQ3Jl7Fxtd+wiN7oaebhP+HAo/1+xWrPqbVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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