SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5356f0150439fe2933ceb54702df575121fffea46002086077bf6fe0529813b7' 
  AND token = 'VBjzOuK3dDyunifHVUCO/1I+yKAUzZkBMXzc3TxisyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00094

JSON explain

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