SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6ff780ad5cd84caa72e428e6570995c9b87b631a54108adc08145819e8f4dbe' 
  AND token = 'JvyZsXFIwWxx2GcMVmJYPkhFybYOHf8/GoAilImprk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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