SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '287c385e6900ae69519fcccffeb09060fa2f6e9869e65bd14d24a6ab15419a65' 
  AND token = 'm1UgjfN2l3aI03NL5a6QleQTsrtHQPFgwwa/spkPhkE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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