SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61883ba306f337f40745eb1b80fb52f72d4ad4f1ae0b039bf6fd9b5dd922294a' 
  AND token = 'pKN15GxaeUu3ZpWeO2Ri2s7/pL8YFLArsQGhSwq9fIE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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