SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4ab84d05fa931fb0f4721585ddea89c4ae3f5fcd4eecd69a39ad98653353b1d' 
  AND token = 'vRB9swP3+KHNBGyv/rr1zXZGB/Wtov86pM1gC7pLvJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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