SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6750ddadb17b7f1d2d4f3212bb12a951fcf564cfa5d16b7dd4ffea25b18672b4' 
  AND token = 'yPInUADW6I57+M8ehaq67VhBTtJoSgUczrhQw9ck0LA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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