SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e7eeb892b1cc42bce585826b150099f48928f019ac97703710ceedd14705323' 
  AND token = 'BfTx/DeBSGyL9QVmxRCrov7EXf7bM/X1sIChOjGWfko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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