SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '795fe4b12b9241e384a2ccd773409d598baa41a61f4ff74258fb4b53ed3aebc6' 
  AND token = '37BFLeKZ9YN7LoVGWCf1cCR0A15X+h4ymgp+n7XwN/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}