SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba62d2eb7cd8b0887add9d08c0bc871ada527db4a874cbd38d41822e47cc5bfe' 
  AND token = 'KShikXJhs1BPzf53sgRoGQtslNcBVZdCNSuQmv6osgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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