SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5635fb0f8a95255b2b3a3183391ddfab5d6f8f6de6ef22707114fd19e42a931' 
  AND token = 'xxngpdvPyfGmNHJpcIpZiZsPhJ6pCT3HW6CRcf7WohA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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