SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '966a14d40064ba10bc0013c4f4697e468f90e788822757b475fac7ee60a5487e' 
  AND token = 'OH8LrPlqBoJT+v/ioCPGVmXG/HjikDmgd/UCRFWCFTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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