SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed574020d1aa1d43d753e1777154964da48f9cb1695cef43de5b861a5c64a3e5' 
  AND token = 'P3ZOpBaf9GXf000Lb9GJ2FTuXPP4M5pNzo/mpAi08+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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