SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5ade9421c143d5507a51d39241230d364ea5400c7ed57bc4ce6a378a832cc15' 
  AND token = 'Xp1/yak3cd+CZKEugAFqaaJzHf2bwfJCwZGTMOFyeOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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