SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0ab926ed7cb29a69236090f18a900ee5cf457e78e51c6e362971f4976136cf0' 
  AND token = 'lRNvc7h+7xvzJvt75/PewXj+jNqupTm/8ILgYJfRxbo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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