SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b92cc2d35d71073a356234c2caba0a1f4ab8875ae8bee9fb0876c5ec4e4ccb4d' 
  AND token = 'XTWQo0LaPyPbDPhmYcuCsOSpbNUUvmrkVfx2S2BXuG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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