SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae6d2f164ae88f5c75da8657002806912c508a06f0df9a1925a5799a8b97e2c8' 
  AND token = 'aH8l0oenIsySASDuE7EB03Nor+3l+rpUcbkoHi960uw=' 
  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"
    }
  }
}